Last week in the town of Krems in Austria, 400 people met to discuss the future of our food system. Delegates from around 40 countries met to discuss how to progress towards "food sovereignty" in Europe. Food sovereignty is a radical proposal for the production and distribution of food that is sustainable, healthy, fair to producers and, above all, democratic. The delegates brought together their experiences of diverse projects across Europe that could contribute to this vision, from organising community-supported agriculture to campaigning against the influence of agribusiness on decision-making.

While the Krems forum was focused on Europe, one of the most interesting things about food sovereignty and the movement that developed it, La Via Campesina, is that much of the momentum comes from the global south. La Via Campesina itself is made up of organisations of small-scale farmers, landless people, fisherfolk and others from north and south, but with a big majority in the south. It formed in the early 1990s as a global response to the growing dominance of agribusiness and the effects structural adjustment was having on farmers.

From the beginning, La Via Campesina was keen to ensure that food producers themselves, rather than external "experts", set the priorities for the movement. The idea of food sovereignty was developed through widespread consultation, and what emerged was not so much a series of policy proposals but a holistic concept that linked the right to food to trade justice, health, stronger democracy and solutions to the climate crisis.

Northern campaign groups tend to be wary of system-wide solutions for fear of being seen as "ideological". Yet today, as the global food system is sucked into the financial crisis through speculation on food commodities, as land is grabbed by financial investors or biofuel companies, and as seed companies return to push genetically modified crops as the solution to climate change, this holistic approach looks rather wise.

Food sovereignty works on many levels. While La Via Campesina rightly demands that small producers have a voice at international bodies such as the UN's Food and Agriculture Organisation, and campaigns nationally and globally for a fair food system, its members aren't just waiting for the right policies to be put into place. From Guatemala to Sri Lanka, peasant farmers are diversifying their farming practices, saving seeds, returning to "natural farming", and forming producer co-operatives to reduce their reliance on corporate players.

They're also taking direct action. The extraordinary growth of Brazil's Landless Workers Movement (MST) has been built on organising people to occupy unused land held by big landowners, and force the government to implement land reform laws to grant them ownership. It may take years, but the MST has settled over 300,000 families in this way. Once they have land they remain involved in the movement because land reform isn't the only problem small farmers face. Direct action isn't normally a strategy that development experts recommend for "lifting people out of poverty", but it has worked in Brazil.

This combination of, on the one hand, practical projects on the ground, and, on the other, confronting the powerful from the conference halls to the fields, has created a strong global movement. The shared ownership of the food sovereignty project has produced a sense of solidarity between hundreds of thousands of farmers who have never met. This popular movement has in turn created a dynamism that has drawn in people beyond the ranks of small rural farmers who are La Via Campesina's main constituency.

Many of these people, along with others – including co-operative distributors, trade unionists from the food industry, organic associations – were represented in Krems last week. We're used to the idea of development experts from rich countries giving poor countries the benefit of their wisdom – or lack of it. On food sovereignty, the solutions are flowing the other way.